It is known in the field of optical temperature and strain sensor technology to distribute sensors along a surface of or within a surface of a structure. Such sensors provide information about the stresses induced at various points on the structure, thereby providing information regarding fatigue, lifetime, and maintenance repair cycles of the structure. Such sensor-integrated structures and the optics that make them functional are known as “smart structures.” One such system is described in U.S. Pat. No. 5,399,854, entitled “Embedded Optical Sensor Capable of Strain and Temperature Measurement Using a Single Diffraction Grating.”
In addition to measuring stresses and temperatures at various points in a structure, it is also desirable to ascertain information regarding corrosion of structural components to determine when the structure is unfit for its normal use. For example, if corrosion occurs at critical stress points along the fuselage or wings of an airplane, structural failure may result.
Thus, it is desirable to obtain a sensor capable of detecting corrosion in structural materials.